Flow deflecting energy dissipation nose sill applied to tail end of spillway

Abstract

The invention relates to the technical field of energy dissipation noses, in particular to a flip bucket applied to the tail end of a spillway. The spillway structure comprises a spillway, and an energy dissipation nose piece is arranged at the tail end of the spillway. According to the energy dissipation nose ridge piece, the structural design of the energy dissipation nose ridge piece is optimized, particularly, the reverse arc guide structure and the corner structure are reasonably arranged, so that the morphological characteristics, speed distribution and the emergent angle of discharged water flow can be more effectively regulated and controlled, and the accurate water flow control mode enables high-speed water flow to form a more uniform flow state when leaving the nose ridge; and the water is cast to a downstream energy dissipation area at a set angle (25-35 degrees), so that the energy dissipation efficiency is improved, the scouring strength to a downstream riverbed and a bank slope is reduced, the depth of a scouring pit is remarkably reduced, and the engineering operation safety is guaranteed. Meanwhile, the measurement assemblies are arranged on a plurality of water depth and flow velocity measurement sections, and the high-precision flow measurement function of the measuring weir constructs a complete hydraulic element monitoring matrix.

Description

Technical Field

[0001] This invention relates to the field of energy dissipation nose sill technology, and more specifically, to an energy dissipation nose sill applied to the end of a spillway. Background Technology

[0002] Traditional spillway designs have a single objective, mainly meeting basic flood discharge needs, and do not pay enough attention to energy dissipation. Under high water head and high flow rate, the energy of the discharged water flow is large, and insufficient energy dissipation will seriously scour the downstream riverbed and banks, threatening the safety of the project. For example, some spillways use simple jet flow energy dissipation, but due to unreasonable jet angle and nose sill design, the water flow cannot effectively diffuse and dissipate energy, resulting in excessively deep scour pits downstream, affecting the long-term stable operation of the project.

[0003] Furthermore, the traditional evaluation index system for spillway design has significant problems. On the one hand, the determination of parameter weights relies excessively on experience and is based on manual weighting, which is highly subjective and lacks scientific quantitative basis. This can easily lead to the underestimation or overestimation of key indicators. For example, when determining the weights of indicators such as energy dissipation efficiency and scour depth, human factors may cause the weight of the critical safety indicator of scour depth to be too low, failing to reflect its importance in the overall evaluation. On the other hand, traditional methods struggle to balance multiple conflicting objectives. For instance, increasing the energy dissipation rate may exacerbate scour depth, but there is no effective means to balance this. Therefore, we propose a diversion energy dissipation nose sill applied to the end of a spillway. Summary of the Invention

[0004] The purpose of this invention is to provide a spillway end-capped energy dissipation nose sill to solve the problems mentioned in the background art of traditional spillway design having a single design objective, limited energy dissipation effect, and insufficient adaptability and flexibility.

[0005] To achieve the above objectives, the present invention provides an energy dissipation nose sill applied to the end of a spillway, comprising a spillway, an energy dissipation nose sill component is provided at the end of the spillway, a measuring weir is provided on one side of the energy dissipation nose sill component, and measuring components are provided on both the energy dissipation nose sill component and the measuring weir for measuring hydraulic elements.

[0006] The structural design of the energy dissipation nose sill allows for the regulation of the morphological characteristics, velocity distribution, and ejection direction of the downstream water flow. Simultaneously, relying on the multi-section synchronous monitoring system of the measurement components, the water depth parameters and three-dimensional velocity field data of each control section along the energy dissipation nose sill are acquired in real time. Combined with the high-precision flow measurement of the measuring weir, a complete hydraulic element monitoring matrix is ​​constructed.

[0007] The beneficial effects of this invention are:

[0008] 1. In this invention, by optimizing the structural design of the energy dissipation nose sill, especially the reasonable arrangement of the anti-arc guide structure and the corner structure, the morphological characteristics, velocity distribution and ejection angle of the downstream water flow can be more effectively controlled. This precise water flow control method makes the high-speed water flow form a more uniform flow pattern when leaving the nose sill, and is projected into the downstream energy dissipation zone at a set angle (25°~35°), thereby improving the energy dissipation efficiency, reducing the scouring intensity of the downstream riverbed and bank slope, significantly reducing the depth of the scour pit, and ensuring the safe operation of the project.

[0009] Meanwhile, the arrangement of measurement components across multiple water depth and velocity measurement sections, along with the high-precision flow measurement function of the measuring weir, constructs a complete hydraulic element monitoring matrix. This matrix can collect water depth parameters, three-dimensional velocity field data, and flow information from each control section in real time, providing comprehensive and continuous data support for analyzing the flow motion state. This data not only helps to dynamically evaluate the energy dissipation effect under different operating conditions but also provides a scientific basis for subsequent structural optimization and operational scheduling.

[0010] 2. This invention introduces a multi-dimensional comprehensive evaluation system combining the entropy weight method and the TOPSIS method. Based on actual monitoring data, the information entropy value of each evaluation indicator is calculated, and its weight is objectively determined, avoiding interference from human factors. This ensures that indicators such as energy dissipation efficiency, crater depth, spillway distance, and average outlet velocity have an importance commensurate with their actual impact in the overall evaluation. This method not only improves the scientific rigor and credibility of the evaluation results but also enhances the rationality of the optimal design scheme.

[0011] As a further improvement to this technical solution, the energy dissipation nose sill includes a reverse arc guide structure connected to the spillway channel. The reverse arc guide structure is an arc-shaped structure used to gradually change the direction of the high-speed water flow flowing down the channel. The bottom of the reverse arc guide structure is provided with a base plate structure, which is a relatively flat structure used to directly bear the impact and pressure of the water flow. Side structures are provided on both sides of the base plate structure, which are used to constrain and guide the water flow. At the end of the base plate structure of the reverse arc guide structure, a corner structure naturally extends, which is used to project the constrained water flow to the downstream energy dissipation zone at a designed angle (25°~35°).

[0012] The beneficial effects of adopting the above-mentioned further solutions are that the synergistic effect of the various structures of the energy-dissipating nose sill component achieves precise control and efficient energy dissipation of the water flow; the anti-arc guide structure, with its arc-shaped design, smoothly changes the direction of the high-speed water flow, laying the foundation for subsequent jetting and avoiding violent impacts when the water flow changes direction; the base plate structure, with its flat surface, directly bears the impact force and pressure of the water flow, ensuring the stability of the overall nose sill structure and preventing damage due to uneven stress; the side structure effectively constrains and guides the water flow, limiting the lateral diffusion of the water flow, ensuring that the water flow follows the preset path, and improving the orderliness of the water flow movement.

[0013] As a further improvement to this technical solution, the measuring components include multiple depth measuring instruments and multiple velocity measuring instruments respectively disposed on the cross-section of the energy dissipation sill, as well as a flow measuring instrument located on the measuring weir; multiple depth measuring sections are provided at the end of the spillway, and multiple depth measuring points are arranged from the left bank to the right bank in each depth measuring section, and the multiple depth measuring instruments are used to measure the depth of each depth measuring section and each depth measuring point; multiple velocity measuring sections are also provided at the end of the spillway, and multiple velocity measuring points are arranged from the left bank to the right bank in each velocity measuring section, and the multiple velocity measuring instruments are used to measure the velocity of the upper, middle and lower layers of each velocity measuring section and each velocity measuring point;

[0014] A water storage tank is provided at the upper end of the spillway, and the water storage tank and the spillway are connected in a continuous manner. The water storage tank is used to provide water for the spillway.

[0015] The beneficial effect of adopting the above-mentioned further scheme is that the measurement component is equipped with multiple water depth and velocity measuring instruments at the cross-section of the energy dissipation nose sill. Combined with the flow measuring instrument of the water measuring weir, a comprehensive hydraulic element monitoring system is constructed. It can accurately capture water depth data at different locations through multiple water depth measuring instruments, reflecting the vertical distribution characteristics of water flow along the nose sill.

[0016] 1. This technology is applied to the spillway end energy dissipation nose sill. By setting up a reverse arc guide structure, it can effectively change the direction of the high-speed water flow from the spillway, so that the water flow can transition to the downstream area more smoothly, thereby reducing the impact of the water flow on the structure. The bottom plate structure of the reverse arc section has a strong load-bearing capacity and can directly withstand the strong impact and pressure brought by the high-speed water flow, improving the stability and durability of the structure. The side structure plays a good role in restraining and guiding the water flow, preventing the water flow from spreading laterally, and further optimizing the water flow pattern.

[0017] Meanwhile, the corner structure that naturally extends from the end of the reverse arc section projects the water flow at a set angle (such as 25°~35°) to the downstream energy dissipation zone, which helps to disperse the energy of the water flow and reduce the risk of scouring and damage to the downstream riverbed or energy dissipation pool.

[0018] 2. This technology is applied to the spillway end energy dissipation sill. The water depth measuring instrument in the measuring component is arranged on multiple cross sections and multiple measuring points are set up along the direction from the left bank to the right bank. It can obtain the water depth changes at different locations and provide accurate data support for analyzing the longitudinal and lateral distribution of water flow.

[0019] The velocity measuring instruments are also distributed across multiple cross-sections, performing three-dimensional velocity measurements at each measuring point, covering the upper, middle, and lower layers. This allows for a comprehensive understanding of the spatial distribution characteristics of water flow velocity, making it particularly suitable for studying the energy dissipation mechanism of high-speed water flow in the sill area. The flow rate measuring instrument is installed on the weir for high-precision measurement of the flow capacity at the end of the spillway. Combined with water depth and velocity data from each cross-section, a complete hydraulic element monitoring matrix is ​​constructed, enabling real-time dynamic control of the entire water flow process.

[0020] 3. This technology, applied to the end-of-spill energy dissipation nose sill, incorporates multiple indicators such as energy dissipation efficiency, sluice depth, sluice distance, and average outlet velocity, moving beyond a single flood discharge objective. By combining the entropy weight method with the (25°~35°)TOPSIS (25°~35°) method to construct a multi-dimensional evaluation system, it can comprehensively assess different layout types of sluice sills, selecting the optimal scheme for effective water flow diffusion and energy dissipation. This solves the problem of balancing multiple conflicting objectives in traditional design. The entropy weight method determines parameter weights, objectively assigning weights based on the actual data variation of each evaluation indicator, avoiding the subjectivity of manual weighting. This ensures that key safety indicators such as sluice depth are reasonably reflected in the overall evaluation, improving the reliability and persuasiveness of the evaluation results, providing a scientific basis for energy dissipation structure design, and further optimizing the layout of the energy dissipation nose sill.

[0021] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure assembly of the present invention;

[0023] Figure 2 This is a demonstration diagram of the angle adjustment of the energy-dissipating nose flap component of the present invention;

[0024] Figure 3 This is a schematic diagram of the energy-dissipating nose flap of the present invention;

[0025] Figure 4 This is a schematic diagram of the arrangement of water depth measuring points at the measurement section of the present invention;

[0026] Figure 5 This is a schematic diagram of the arrangement of flow velocity measuring points in the measurement section of the present invention;

[0027] Figure 6 This is a schematic diagram of the measurement component of the present invention;

[0028] Figure 7 This is a schematic diagram of the experimental scheme of the present invention;

[0029] The meanings of the labels in the diagram are as follows:

[0030] 100. Spillway;

[0031] 200. Energy-absorbing nose sill component; 201. Reverse arc guide structure; 202. Base plate structure; 203. Side structure; 204. Corner structure;

[0032] 300. Water measuring weir;

[0033] 400. Measurement components;

[0034] 500. Reservoir. Detailed Implementation

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] The present invention provides the following preferred embodiments.

[0037] Please see Figure 1 - Figure 7 As shown, this embodiment provides an energy dissipation nose sill applied to the end of a spillway, including a spillway 100, an energy dissipation nose sill 200 at the end of the spillway 100, a measuring weir 300 on one side of the energy dissipation nose sill 200, and a measuring component 400 on both the energy dissipation nose sill 200 and the measuring weir 300 for measuring hydraulic elements.

[0038] Through the structural design of the energy dissipation nose sill 200, the morphological characteristics, velocity distribution and ejection direction of the downstream water flow are regulated; at the same time, relying on the multi-section synchronous monitoring system of the measurement component 400, the water depth parameters and three-dimensional velocity field data of each control section along the energy dissipation nose sill 200 are acquired in real time, and combined with the high-precision flow measurement of the measuring weir 300, a complete hydraulic element monitoring matrix is ​​constructed.

[0039] Based on the above, the energy dissipation effect is enhanced by optimizing the firing angle and the shape of the nose cone, and a multi-dimensional evaluation system is constructed by combining the entropy weight method and the TOPSIS method.

[0040] Therefore, based on the above features, the improvements of the present invention will be described in detail:

[0041] In order to meet basic flood discharge needs, the spillway 100 has not paid enough attention to energy dissipation. When the water head and flow rate are high, the energy of the downstream water flow is large. Insufficient energy dissipation will seriously scour the downstream riverbed and banks, threatening the safety of the project. For example, some spillways 100 adopt simple jet flow energy dissipation. Due to unreasonable jet angle and nose sill design, the water flow cannot effectively diffuse and dissipate energy, resulting in excessively deep downstream scour pits, which affects the long-term stable operation of the project.

[0042] Therefore, by optimizing the structural design of the energy dissipation nose sill 200, the morphological characteristics, velocity distribution, and ejection direction of the discharged water flow can be precisely controlled to achieve efficient energy dissipation. At the same time, based on the multi-section synchronous monitoring system of the measurement component 400, the water depth parameters and three-dimensional velocity field data of each control section along the energy dissipation nose sill 200 are collected in real time. Combined with the high-precision flow metering of the measuring weir 300, a complete hydraulic element monitoring matrix is ​​constructed, thereby providing multi-dimensional data support for energy dissipation efficiency assessment.

[0043] In terms of improving energy dissipation, the limitations of a single flood discharge objective have been overcome. Multiple indicators, such as energy dissipation efficiency, sluice depth, spillway distance, and average outlet velocity, have been incorporated into the design considerations. For the spillway 100, which adopts spillway energy dissipation, the energy dissipation effect is enhanced by optimizing the spillway angle and the nose sill form. A multi-dimensional evaluation system constructed by combining the entropy weight method and the TOPSIS method is used to evaluate different types of twisted nose sills and select the best scheme that can effectively diffuse and dissipate energy, reducing the problem of excessively deep downstream sluices caused by unreasonable design. At the same time, experimental and simulation data are used to fully analyze the motion state of water flow under different nose sill arrangements, providing a scientific basis for the design of energy dissipation structures.

[0044] Because the determination of parameter weights relies excessively on experience and involves manual weighting, it is highly subjective and lacks scientific quantitative basis. This can easily lead to the underestimation or overestimation of key indicators. When determining the weights of indicators such as energy dissipation efficiency and crater depth, human factors may cause the weight of crater depth, a critical safety indicator, to be too low, failing to reflect its importance in the overall evaluation. Therefore, the entropy weight method is adopted as the method for determining parameter weights. Based on the theory of information entropy, the entropy weight method objectively assigns weights by analyzing the actual data variation of each evaluation indicator (such as energy dissipation efficiency, crater depth, spillway distance, and average outlet velocity), avoiding the underestimation of weights due to subjective human judgment and ensuring their importance in the overall evaluation. The importance of the evaluation is reasonably reflected. This method determines the weights entirely based on the characteristics of the data itself, without relying on experience, which can effectively reduce the interference of human factors and provide an objective and scientific quantitative basis for the multi-index evaluation system. At the same time, the entropy weight method is combined with the TOPSIS method. The objective weights obtained by the entropy weight method are used to weight each index, and then the TOPSIS method is used to calculate the closeness of each scheme to the ideal solution, so as to achieve the comprehensive ranking of multiple schemes. In this process, the weights of each index are determined by data, so that key safety indicators such as crater depth play their due role in the scheme trade-off, and improve the reliability and persuasiveness of the evaluation results.

[0045] Based on the above, the specific structure will be disclosed in detail:

[0046] Considering the need to regulate the morphological characteristics, velocity distribution, and ejection direction of the discharged water flow, the energy-dissipating nose sill component 200 is disclosed in detail, such as... Figure 2 and Figure 3 As shown, the energy-dissipating nose sill 200 includes a reverse arc guide structure 201 connected to the spillway 100 trough. The reverse arc guide structure 201 is an arc-shaped structure used to gradually change the direction of the high-speed water flow flowing down the trough.

[0047] The bottom of the anti-arc guide structure 201 is provided with a base plate structure 202. The base plate structure 202 is a relatively flat structure, which is used to directly bear the impact force and pressure of the water flow.

[0048] The bottom plate structure 202 is provided with side structures 203 on both sides, which are used to constrain and guide the water flow;

[0049] The bottom plate structure 202 of the anti-arc guide structure 201 naturally extends into a corner structure 204. The corner structure 204 is used to project the constrained water flow to the downstream energy dissipation zone at a design angle (25°~35°).

[0050] Therefore, the anti-arc guide structure 201 uses the arc surface to guide the water flow to change direction, and uses centrifugal force to change the trajectory of the water flow, smoothly transitioning the horizontal flow of the chute to a high-speed flow to an upward inclined direction, giving the water flow an upward initial velocity; the bottom plate structure 202 withstands the impact of the water flow with its flat surface, and disperses the force of the water flow on the nose sill through friction and pressure transmission with the water flow; the side structure 203 uses the obstruction on both sides to form a constrained space, restricting the lateral diffusion of the water flow, so that the water flow flows along a preset path and reduces the disorder of energy loss; the corner structure 204, through the end tilt angle (25°~35°), gives the water flow a specific projection angle based on the law of projectile motion, allowing the water flow to obtain horizontal and vertical velocity components.

[0051] Furthermore, to achieve the measurement of hydraulic elements, the 400-unit measurement assembly is disclosed in detail, specifically as follows: Figure 4 - Figure 6 As shown, the measuring component 400 includes multiple depth measuring instruments and multiple velocity measuring instruments respectively disposed on the cross section of the energy dissipation nose sill 200, as well as a flow measuring instrument located on the measuring weir 300.

[0052] Multiple water depth measurement sections are set at the end of the spillway 100, and multiple water depth measuring points are arranged from the left bank to the right bank at each water depth measurement section. Multiple water depth measuring instruments are used to measure the water depth of each water depth measurement section and each water depth measuring point. In order to reduce the influence of the sidewall viscosity on the measurement results, the water depth measuring points on the left and right banks near the sidewall should be kept at a certain distance from the sidewall of the channel.

[0053] Multiple velocity measurement sections are also set at the end of the spillway 100, and multiple velocity measuring points are arranged from the left bank to the right bank at each velocity measurement section. Multiple velocity measuring instruments are used to measure the velocity of the upper, middle and lower layers of each velocity measurement section and each velocity measuring point.

[0054] The flow meter is used to measure the flow rate of the energy dissipation nose sill 200 at the end of the spillway 100.

[0055] However, to achieve the supply of 100 cubic meters of water to the spillway, specifically as follows: Figure 1 - Figure 6 As shown, a water storage tank 500 is provided at the upper end of the spillway 100. The water storage tank 500 and the spillway 100 are connected and the water storage tank 500 is used to provide water for the spillway 100. Therefore, it can be ensured that the spillway 100 can obtain a continuous and controllable water flow under different operating conditions. When it is necessary to test the performance of the energy dissipation nose sill 200 or to conduct related tests, the water storage tank 500 can adjust the water discharge flow according to the test requirements, providing stable water flow conditions for the measuring component 400 to monitor parameters such as water depth, flow velocity, and flow rate, and ensuring the reliability and consistency of the test data.

[0056] Based on the above, multiple experiments were conducted using various methods. Specific experimental diagrams are attached to the instruction manual. Figure 7 The experimental data are as follows:

[0057] Step 3: Establish a multi-objective evaluation system for the energy dissipation effect of the convection channel's end sill.

[0058] The weights of the lift distance, energy dissipation rate, and average outlet velocity are determined using the entropy weight method.

[0059] Indicator Standardization

[0060] Suppose that the elements of the data matrix X after index standardization are... The outlet distance (X) and energy dissipation rate (P) are positive indicators, while the average outlet velocity (V) is a negative indicator.

[0061] (a) Indicator type conversion (positive / negative)

[0062] Unify the direction of all indicators (make them all positive indicators, i.e., the larger the value, the better).

[0063] For positive indicators (lifting distance, energy dissipation rate): (Keep the original number) (1)

[0064] For negative indicators (average export velocity):

[0065] (2)

[0066] (b) Standardization (normalization to the [0,1] interval)

[0067] Eliminate dimensional differences to make different indicators comparable.

[0068] (3)

[0069] Results: All indicator values ∈[0,1], and all are positive (the larger the value, the better).

[0070] ② Calculate information carrying capacity

[0071] Information entropy is used to measure the "uncertainty" of an indicator. The smaller the entropy value, the more uneven the data distribution of the indicator, and the greater the amount of information it provides.

[0072] Calculate information entropy: (4)

[0073] in

[0074] When all When the data are equal (i.e., the data are completely uniform), the entropy value is the maximum. This indicates that the indicator provides the least amount of information.

[0075] When a certain (Other values ​​are 0), the entropy value is the minimum. This indicates that the indicator contains the most information.

[0076] ③ Calculate the weights of sub-evaluation indicators

[0077] The greater the information capacity, the higher the weight. The larger the value, the weighting formulas for the lift distance (X), energy dissipation rate (P), and average outlet velocity (V) are as follows:

[0078] (5) ④ Construction of the Comprehensive Energy Consumption Index (SS)

[0079] After determining the weights of the pick-up distance (X), energy dissipation rate (P), and average outlet velocity (V) using the entropy weight method, the three are combined into a comprehensive energy dissipation index (SS), which is calculated using the following formula:

[0080] (6)

[0081] The weights are objectively calculated using the entropy weight method. This index, through normalization to eliminate dimensional differences, can directly quantify the comprehensive performance of spillway energy dissipation under different operating conditions, achieving multi-objective collaborative optimization.

[0082] Step 4 uses the TOPSIS method for dynamic sorting (based on the SS index).

[0083] (1) Standardization processing (since the SS index has been normalized, it can be used directly)

[0084]

[0085] (2) Construct the weighted matrix

[0086] (7)

[0087] (3) Calculate the distance between each scheme and the positive / negative ideal solution.

[0088] Positive Ideal Solution (8)

[0089] Negative ideal solution (9)

[0090] (4) Calculate proximity

[0091] (10)

[0092] (11)

[0093] (12)

[0094] according to The optimal solution is determined by sorting.

[0095] 5. Advantages and positive effects

[0096] (1) The ability of multi-objective collaborative optimization has been significantly improved.

[0097] (a) Objective weight allocation:

[0098] The entropy weight method is used to calculate the weight of indicators based on the data dispersion, avoiding the subjective bias of traditional manual weighting and ensuring that key indicators are not underestimated.

[0099] (b) Dynamic decision optimization:

[0100] The TOPSIS method was used to dynamically sort the results of 27 sets of experiments, achieving synergistic optimization of energy dissipation efficiency, average outlet velocity and pick-up distance, which improved energy dissipation efficiency by 11% (from 82% to 93%) compared with the traditional single-objective design.

[0101] (2) In-depth optimization of experimental techniques

[0102] (a) High-precision data support:

[0103] (a) 1:35 geometric scale hydraulic model test accurately captures water flow characteristics (such as scour pit morphology and water tongue trajectory). (b) Flow regime control optimization:

[0104] Experiments have shown that after optimization, undesirable flow patterns (backflow, vortex) are significantly reduced, flow field uniformity is improved, and the risk of cavitation is reduced.

[0105] (3) Breakthrough in engineering applicability and efficiency

[0106] The optimized nose sill parameter combination (Scheme 9) can be directly applied to actual projects (such as the Santunhe Reservoir). Its synergistic improvement in energy dissipation effect (high energy dissipation rate, low outlet flow velocity, and reasonable cantilever distance) can shorten the design verification cycle by more than 50% and significantly reduce the later maintenance costs.

[0107] (4) Innovative application of the comprehensive energy consumption efficiency index (SS)

[0108] (a) Unified evaluation based on multiple indicators:

[0109] The SS index combines the cantilever distance, energy dissipation rate, and outlet velocity into a single quantitative indicator, which intuitively reflects the overall performance and avoids the trade-off difficulties caused by the conflict of multiple objectives in traditional design.

[0110] (b) Dynamic optimization to improve efficiency:

[0111] The TOPSIS ranking method based on the SS index quickly selects the optimal combination of nasal sill parameters for comprehensive energy dissipation.

[0112] Step 2: Experimental Design

[0113] The experiment focused on the spillway's energy dissipation efficiency and flow control objectives, selecting eight key parameters for comparative analysis: discharge flow rate (Q), tilt angle (θ), radius of inversion (R), nose sill length (L), inlet width (B), nose sill elevation (Z), left wall contraction angle (α1), and right wall contraction angle (α2). The discharge flow rate (Q) covered the actual operating range from the design flood level (99.73 m³ / s) to the check flood level (210.08 m³ / s). Tilting angle (θ) and radius of inversion (R) were used as core variables to adjust the diffusion range of the water jet trajectory and the smoothness of the flow direction, respectively. Nose sill length (L) and inlet width (B) optimized the flow field distribution by controlling water contraction and diffusion. Nose sill elevation (Z) affected the water flow potential energy conversion efficiency and needed to be matched with the downstream apron elevation. The sidewall contraction angles (α1, α2) were used to regulate the lateral diffusion of the water flow, avoiding localized scouring and energy concentration.

[0114] Step 4: Experimental Data

[0115] The following experimental data were obtained based on the hydraulic element measurement in Step 2 of Section 4.

[0116] Table 1: Experimental Data Table

[0117]

[0118] Step 5: Calculation of the weights of each evaluation indicator

[0119] The weights of each evaluation index are calculated according to formulas (1)-(5) in section 4. Technical Content. The specific calculation results are shown in Table 2.

[0120] Table 2: Weight Allocation of Evaluation Indicators

[0121]

[0122] Step 6: Obtaining Experimental Results

[0123] Data measurement;

[0124] By measuring water depth, flow velocity, flow rate, and other flow-related parameters, we can estimate the lift distance, energy dissipation rate, and average outlet velocity, which are related to the flow action.

[0125] Calculate the weights of the cantilever distance, energy dissipation rate, and average outlet velocity respectively.

[0126] All schemes in Table 3 use uniform weights (displacement 33.75%, energy dissipation rate 32.32%, outlet velocity 33.93%), which is consistent with the output results of the entropy weight method.

[0127] Calculation of the Comprehensive Energy Consumption Index (SS):

[0128] By substituting the weights calculated above into formula (6), the comprehensive energy consumption index corresponding to the three evaluation indicators is obtained. The specific results are shown in Table 3.

[0129] TOPSIS dynamic sorting:

[0130] The TOPSIS proximity and the distance to the positive and negative ideal solutions are calculated using equations (7) to (12) to rank the nine working conditions.

[0131] Table 3: SS Index Calculation Results

[0132]

[0133]

[0134] Step 8: Key Conclusions

[0135] Experimental results show that the spillway angle (θ) and the radius of the reverse arc (R) are the core parameters affecting the energy dissipation efficiency and flow control of the spillway. Based on the multi-objective collaborative optimization requirements, increasing the spillway angle from 25° to 36° (enhancing the diffusion of water jet kinetic energy) significantly extends the spillway distance (45.2m→68.3m); increasing the radius of the reverse arc from 20.0m to 25.0m (reducing the centrifugal constraint of the water flow and improving energy conversion) effectively reduces the average flow at the outlet (12.8m / s→7.2m / s), while increasing the energy dissipation rate by 11% (82%→93%). Optimizing the left wall contraction angle (α1) to 10° (balancing lateral diffusion and scour control) can eliminate local scour of the apron. Scheme 9 achieves a synergistic effect of maximizing the cantilever distance (68.3m), achieving the highest energy dissipation rate (93%), and the lowest outlet velocity (7.2m / s) by combining a high cantilever angle (36°), a large reverse arc radius (25.0m), and simultaneous optimization of the contraction angle double walls (α1=α2=10°). This essentially eliminates undesirable flow patterns (improved flow field uniformity and reduced cavitation risk). TOPSIS dynamic sorting proximity ( =1.00), and finally the nose sill arrangement with the best overall energy dissipation effect was obtained.

[0136] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A spillway end energy dissipation sill, comprising a spillway (100), characterized in that: An energy dissipation nose sill (200) is provided at the end of the spillway (100), and a water measuring weir (300) is provided on one side of the energy dissipation nose sill (200). A measuring component (400) is provided on both the energy dissipation nose sill (200) and the water measuring weir (300) for measuring hydraulic elements. Through the structural design of the energy dissipation nose sill (200), the morphological characteristics, velocity distribution and ejection direction of the downstream water flow are controlled; at the same time, relying on the multi-section synchronous monitoring system of the measurement component (400), the water depth parameters and three-dimensional velocity field data of each control section along the energy dissipation nose sill (200) are acquired in real time, and combined with the high-precision flow measurement of the water measuring weir (300), a complete hydraulic element monitoring matrix is ​​constructed.

2. The energy dissipation sill applied to the end of a spillway as described in claim 1, characterized in that: The energy dissipation nose sill (200) includes a reverse arc guide structure (201) connected to the spillway (100) trough. The reverse arc guide structure (201) is an arc-shaped structure used to gradually change the direction of the high-speed water flow flowing down the trough. The spillway (100) is used to ensure the safety of the dam and its ancillary facilities.

3. The energy dissipation nose sill applied to the end of a spillway according to claim 2, characterized in that: The bottom of the anti-arc guide structure (201) is provided with a base plate structure (202), which is a relatively flat structure used to directly withstand the impact and pressure of the water flow.

4. The energy dissipation nose sill applied to the end of a spillway according to claim 3, characterized in that: The bottom plate structure (202) is provided with side structures (203) on both sides, which are used to constrain and guide the water flow.

5. The spillway end energy dissipation sill as described in claim 3, characterized in that: The bottom plate structure (202) of the anti-arc guide structure (201) naturally extends into a corner structure (204) at the end. The corner structure (204) is used to project the constrained water flow to the downstream energy dissipation zone at a design angle (25°~35°).

6. The energy dissipation nose sill applied to the end of a spillway according to claim 1, characterized in that: The measuring assembly (400) includes multiple depth measuring instruments and multiple velocity measuring instruments respectively disposed on the cross section of the energy dissipation nose sill (200) and a flow measuring instrument located on the measuring weir (300).

7. The energy dissipation nose sill applied to the end of a spillway according to claim 6, characterized in that: The spillway (100) has multiple water depth measurement sections at its end, and each water depth measurement section has multiple water depth measuring points arranged from the left bank to the right bank. Multiple water depth measuring instruments are used to measure the water depth of each water depth measurement section and each water depth measuring point.

8. The energy dissipation nose sill applied to the end of a spillway according to claim 6, characterized in that: The spillway (100) is also provided with multiple velocity measurement sections at its end, and multiple velocity measuring points are arranged from the left bank to the right bank for each velocity measurement section. The multiple velocity measuring points are used to ensure the accuracy of the data of each velocity measurement section, and the multiple velocity measuring instruments are used to measure the velocity of each velocity measurement section and each velocity measuring point in the upper, middle and lower layers.

9. The spillway end energy dissipation nose sill as described in claim 6, characterized in that: The flow meter is used to measure the flow rate of the energy dissipation nose sill (200) at the end of the spillway (100).

10. The energy dissipation nose sill applied to the end of a spillway according to claim 1, characterized in that: A water storage tank (500) is provided at the upper end of the spillway (100), and the water storage tank (500) and the spillway (100) are connected in a continuous manner, and the water storage tank (500) is used to provide water to the spillway (100).

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